The case on Monday's Castle(10/9c, ABC) hits a little too close to home.

That's especially true for Detective Ryan (Seamus Dever), who last season lost his badge and service weapon to the 3XK serial killer. Now, the missing gun has turned up — as the weapon that murdered the team's most recent victim.

"It's a very emotional episode for Detective Ryan," creator and executive producer Andrew W. Marlowe tells TVGuide.com. "If you're a cop and you've lost your gun to somebody, and then it's used in a murder, the case becomes deeply, deeply personal to you. It's every cop's worst nightmare...